The Common Raven (Corvus corax), also known as the Northern Raven, is a large, all-black passerine bird. Found across the northern hemisphere, it is the most widely distributed of all corvids. There are at least eight subspecies with little variation in appearance— although recent research has demonstrated significant genetic differences among populations from various regions. It is one of the two largest corvids, alongside the Thick-billed Raven, and is possibly the heaviest passerine bird; at maturity, the Common Raven averages 63 cm (25 inches) in length and 1.2 kg (2.6 pounds). Common Ravens typically live about 10 to 15 years in the wild, although lifespans of up to 40 years have been recorded. Young birds may travel in flocks, but later mate for life, with each mated pair defending a territory.

The Common Raven has coexisted with humans for thousands of years and in some areas has been so numerous that it is considered a pest. Part of its success comes from its omnivorous diet; Common Ravens are extremely versatile and opportunistic in finding sources of nutrition, feeding on carrion, insects, cereal grains, berries, fruit, small animals, and food waste.

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Other names

Description

Subspecies

While some authorities recognized as many as 11 subspecies,[3] others only recognize eight:[4]

C. c. corax (the nominate subspecies) occurs from Europe eastwards to Lake Baikal, south to the Caucasus region and northern Iran. It has a relatively short, arched bill. The population in south-western Europe (including the Balearic Islands, Corsica and Sardinia) has an even more arched bill and shorter wings than "typical" nominate, leading some authorities to recognize it as a separate subspecies, C. c. hispanus.[3]

C. c. varius occurs in Iceland and the Faroe Islands. It is less glossy than C. c. principalis or nominate corax, is intermediate in size, and the bases of its neck feathers are whitish (not visible at a distance). An extinctcolor morph found only on the Faroes is known as Pied Raven

C. c. subcorax occurs from Greece eastwards to north-west India, Central Asia and western China though not the Himalayan region. It is larger than the nominate form, but has relatively short throat feathers (hackles). Its plumage is generally all black, though its neck and breast have a brownish tone similar to that of the Brown-necked Raven; this more evident when the plumage is worn. The bases of its neck feathers, although somewhat variable in colour, are often almost whitish. (The name C. c. laurencei is sometimes used instead of C. c. subcorax.[3] It is based on the population from Sindh described by Hume in 1873[5] and is sometimes preferred since the type specimen of subcorax collected by Nikolai Severtzov is possibly a Brown-necked Raven[6])

C. c. tingitanus occurs in North Africa and the Canary Islands. It is the smallest subspecies, with the shortest throat hackles and a distinctly oily plumage gloss. Its bill is short but markedly stout, and the culmen is strongly arched. Canary Ravens are browner than the North African Ravens, leading some authorities to treat them as separate subspecies, with the latter maintaining the name C. c. tingitanus and the former known as C. c. canariensis.[3]

C. c. tibetanus occurs in the Himalayas. It is the largest and glossiest subspecies, with the longest throat hackles. Its bill is large but less imposing than that of C. c. principalis, and the bases of its neck feathers are grey.

C. c. kamtschaticus occurs in north-eastern Asia, intergrading into the nominate subspecies in the Baikal region. It is intermediate in size between C. c. principalis and C. c. corax and has a distinctly larger and thicker bill than does the nominate race.

C. c. principalis occurs in northern North America and Greenland. It has a large body and the largest bill, its plumage is strongly glossed, and its throat hackles are well developed.

C. c. sinuatus, the Western Raven, occurs in south-central USA and Central America. It is smaller, with a smaller and narrower bill than C. c. principalis. Populations in far south-western USA and north-western Mexico (including the Revillagigedo Islands) are the smallest in North America. They are sometimes included in C. c. sinuatus, while other authorities recognize them as a distinct subspecies, C. c. clarionensis.[3]